Space Mechanic | Today’s Space News

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Language: en

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Somewhere above your head right now,


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about 36,000 km up, there is a graveyard


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shift going on. Hundreds of satellites


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still working, still useful, and slowly


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running out of fuel.


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>> And as of last night, there is finally a


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mechanic on the way.


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>> Good evening and welcome to Astronomy


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Daily. I'm Anna.


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>> And I'm Avery. Coming up, a spacecraft


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with arms launches on a mission to keep


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other spacecraft alive. A rocket stage


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is two weeks out from hitting the moon,


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and astronomers have just put out a call


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to arms about it.


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>> We've got two stars that were born


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together, lived together, and then died


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in sequence, leaving behind the first


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pair of supernova remnants ever traced


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back to a single binary. the first


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complete magnetic map of a galaxy


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cluster, an asteroid breakup that may


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have bombarded three worlds and helped


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freeze our own,


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>> and a skywatching window that is closing


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faster than you'd like.


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>> Let's get into it.


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>> So, Avery, here's a problem that has


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quietly bothered the satellite industry


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for about 60 years. You build a


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satellite. You spend hundreds of


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millions of dollars on it. You put it in


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geostationary orbit 35,786


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km up where it hovers over the same


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patch of ground forever and it works


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beautifully for 15 years and then it


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runs out of fuel


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>> and that's it. The hardware is fine.


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>> The hardware is often perfectly fine.


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The cameras work, the transponders work,


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the solar panels work, but without


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propellant, it can't hold its position.


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So, it drifts and it becomes junk. You


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throw away a working satellite because


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the tank is empty.


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>> That is a spectacularly wasteful way to


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run an industry.


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>> It is. And last night, Northre Grumman


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launched the most serious attempt yet to


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fix it. At 5:15 in the evening, Eastern


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time on Tuesday the 21st of July, the


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Falcon 9 lifted off from Space Launch


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Complex 40 at Cape Canaveral carrying


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the mission robotic vehicle plus three


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mission extension pods.


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>> Mission robotic vehicle. What does it


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actually look like? Picture a satellite


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bus with two arms, two robotic arms,


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each about 3 m long, 10 ft, built by the


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United States Naval Research Laboratory


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and supplied through DARPA's robotic


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servicing of geostationary satellite


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program.


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>> So this is a genuinely dextrous machine,


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not just the tug that bolts on.


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>> That's the distinction that matters. The


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MRV can inspect, it can relocate, it can


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repair, it can upgrade, and its headline


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job on this mission is to pick up those


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three mission extension pods and install


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them on client satellites that are


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running low on propellant.


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>> So, the pods are the actual fuel


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solution.


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>> Think of them as jetpacks. Each pod


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clamps onto a satellite and takes over


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orbit control and momentum management


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using electric propulsion. Each one can


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handle a satellite of about 2,000 kg.


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That's a typical big geostationary bird.


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And give it up to 8 more years of life.


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>> 8 years on a satellite that was


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otherwise finished.


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>> 8 years. And the MRV itself carries


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something called a passive refueling


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interface, which is the first refueling


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interface approved by the US Space


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Force. So, the servicer is itself


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designed to be refueled later.


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>> Now, Northrub have done a version of


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this before, haven't they?


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>> They have, and this is why they're the


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ones doing it. Bish extension vehicle 1


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launched in October 2019. The first


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commercial satellite servicing


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spacecraft ever. And 4 months later, it


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docked with communication satellite


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Intelsat 901 in geostationary orbit.


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MEV2 followed in August 2020.


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>> So what's different this time?


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>> Those earlier vehicles were one to one.


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One serer went to one satellite, docked


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with it, and stayed there doing the work


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itself. The MRV is one to many. It


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carries pods, installs them, and moves


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on. It's the difference between a tow


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truck that has to stay attached to your


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car forever and a mechanic who fits a


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new part and drives off to the next job.


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That scales.


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>> That scales. And there's a nice detail


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on the launch itself. The Falcon 9


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booster B1069


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was flying its 302nd mission and it was


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deliberately expended. No landing.


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>> Why give up a booster with 31 flights on


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it? Because GEO's stationary transfer


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orbit is demanding. Getting that much


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mass that high needed every bit of


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performance the rocket had. And there


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wasn't propellant left for a landing


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burn. SpaceX made the trade.


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>> So when does the actual servicing start?


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>> Not for a while. The MRV and the three


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pods each separate and then climb to


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geostationary orbit under their own


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solar electric propulsion. And that


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climb takes up to a year. Servicing


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operations are expected to begin in


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2027. After the initial checkouts, the


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RSGS program gets handed over to the US


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Space Force.


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>> A year of just going up


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>> slowly and efficiently. Electric


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propulsion is patient. And at the end of


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it, for the first time, there's a repair


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capability parked permanently in the


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most valuable orbital real estate we


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have.


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>> Right. From a machine built to preserve


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spacecraft to a spacecraft that is about


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to be very thoroughly destroyed.


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>> This is one we've been tracking.


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>> It is. And I want to be upfront about


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that. We covered this back in June in


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episode 125. But there is a genuine


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reason to come back to it because the


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science community has just done


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something about it. The short version


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for anyone joining us since in January


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2025, a Falcon 9 launched two commercial


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lunar landers, Fireflyy's Blue Ghost and


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iSpace's Hakuto R Mission 2. It did its


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job, but the upper stage cataloged as


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202510D


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never came home. Instead of burning up


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in our atmosphere, it ended up in a long


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looping orbit through the Earth Moon


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system. And somebody noticed.


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>> The independent astronomer Bill Gray,


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who runs Project Pluto and tracks this


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sort of high orbit debris, his software


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flagged an impact. On the 5th of August


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this year, that stage hits the moon.


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>> So, what's new? Three things. First, a


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new preprint has just gone up on archive


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and it is signed by 23 astronomers. It


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is essentially a call to arms. They're


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asking the scientific community,


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professional and amateur, to point


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everything they've got at the moon on


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the 5th of August


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>> because this is a rare thing


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>> because we almost never get this. We get


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natural impacts on the moon all the


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time, but we don't know when they're


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coming. Here, we know the object. We


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know its mass. We know its structure. We


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know its velocity. And we know the time


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to within about a second. That is an


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artificial impact experiment we didn't


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have to pay to set up.


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>> And the timing has been tightened,


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hasn't it?


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>> That's a second. You think Gray's latest


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published calculation dated the 17th of


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July puts the impact at 634 and 32


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seconds UTC. Earlier coverage back in


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May was quoting 644. So, if you've got


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the old number written down, update it.


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>> And the third,


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>> the third is the actual physics


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prediction. And this is the part I find


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genuinely interesting. The paper models


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what happens on contact. This thing is


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roughly 12 m long and about 4,000 kg.


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And crucially, it's hollow. It's a tank.


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So, the prediction is that it crushes


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rather than punching deep.


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>> Like a can rather than a bullet.


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>> Exactly like a can. And the result of


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that is a relatively shallow crater.


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They're estimating 20 to 30 meters


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across, but a very large eject plume.


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Kilometers of debris thrown up off the


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surface.


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>> So, the plume might be the visible part.


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>> That's the hope. And it's a subtle bit


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of reasoning. The impact site is near


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the crater Einstein, right on the moon's


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western limb, about the 10:00 position


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on the disc as you look at it. Now,


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that's awkward because it's on the


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sunlit part of the surface and no impact


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flash, artificial or natural, has ever


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been recorded on the lit face of the


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moon. The glare defeats you,


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>> but being on the limb helps.


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>> Being on the limb might save it because


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rocks thrown up from a site that close


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to the edge rise off the moon entirely.


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And once they're off the limb, they're


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silhouetted against black sky catching


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sunlight. So you might not see the


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flash, but you might see the plume.


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>> Who else is watching?


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>> NASA's Lunar Reconnaissance Orbiter will


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image the site before and after, which


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gives a clean comparison. And South


00:09:30.320 --> 00:09:32.389
Korea's Pathfinder Lunar Orbiter is


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going to attempt to observe as well.


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There's precedent for the after image,


00:09:36.240 --> 00:09:38.630
too. When a Chinese rocket stage hit the


00:09:38.640 --> 00:09:41.910
far side in 2022, LRO found the site,


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and it had made not one crater, but two.


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>> And there's a longer term payoff to all


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this. And this is why the paper matters


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beyond the spectacle. They want to test


00:09:51.920 --> 00:09:54.230
a method for pinpointing exactly where


00:09:54.240 --> 00:09:56.230
an object strikes the moon using the


00:09:56.240 --> 00:09:58.630
observations. If you can nail that down


00:09:58.640 --> 00:10:01.350
against a known impact, you validated a


00:10:01.360 --> 00:10:03.829
technique and that feeds directly into


00:10:03.839 --> 00:10:05.750
planning seismic experiments on the


00:10:05.760 --> 00:10:07.910
lunar surface for future missions.


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>> Now, the practical question, who


00:10:10.080 --> 00:10:12.389
actually gets to see this? And this is


00:10:12.399 --> 00:10:14.310
where our North American listeners want


00:10:14.320 --> 00:10:16.710
to pay attention because this one is


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squarely yours. 6:34 UTC on the 5th of


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August is 29 minutes past 2:00 in the


00:10:23.120 --> 00:10:26.470
morning Eastern time, 1:34 central,


00:10:26.480 --> 00:10:29.190
12:34 Mountain, and on the West Coast,


00:10:29.200 --> 00:10:31.910
it's still the night before, 11:34 in


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the evening on the 4th.


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>> Middle of the night, but the moon is


00:10:35.440 --> 00:10:37.829
well up. The moon is wellplaced across


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the continent and the paper specifically


00:10:40.320 --> 00:10:42.630
identifies observers in the Americas as


00:10:42.640 --> 00:10:45.190
the ideal group. If you have a telescope


00:10:45.200 --> 00:10:47.190
and you've ever wanted to contribute to


00:10:47.200 --> 00:10:49.910
something real, this is the night. They


00:10:49.920 --> 00:10:52.150
are explicitly asking amateurs to take


00:10:52.160 --> 00:10:52.790
part.


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>> And for those of us further around the


00:10:54.720 --> 00:10:55.590
globe,


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>> less kind, and I'll be straight about


00:10:57.440 --> 00:11:00.470
it. For us in Australia, that's 4:34 in


00:11:00.480 --> 00:11:02.870
the afternoon. Broad daylight. New


00:11:02.880 --> 00:11:05.670
Zealand, early evening, no good either.


00:11:05.680 --> 00:11:08.230
The UK and Europe get half 7 in the


00:11:08.240 --> 00:11:10.630
morning which is also daylight. So the


00:11:10.640 --> 00:11:13.110
live event belongs to the Americas.


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>> But the aftermath belongs to everyone.


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>> The aftermath belongs to everyone. The


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LRO before and after imagery, the crater


00:11:20.720 --> 00:11:23.030
measurements, the analysis of how well


00:11:23.040 --> 00:11:25.269
the predictions held up. And frankly,


00:11:25.279 --> 00:11:27.030
the question sitting underneath all of


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this is global. We are about to start


00:11:29.360 --> 00:11:31.750
putting people back on the moon. and we


00:11:31.760 --> 00:11:33.509
are currently hitting it with our own


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rubbish by accident without warning.


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>> All right, Avery, moving on to our next


00:11:38.800 --> 00:11:41.750
story. More than half of all stars are


00:11:41.760 --> 00:11:44.870
in multiple systems, two or more suns


00:11:44.880 --> 00:11:47.269
orbiting each other. And for the really


00:11:47.279 --> 00:11:49.509
massive stars, the ones destined to


00:11:49.519 --> 00:11:52.949
explode, that fraction is even higher.


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>> So most supernovas should have had a


00:11:54.959 --> 00:11:55.750
sibling.


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>> That is exactly the implication. And yet


00:11:58.560 --> 00:12:01.110
until this week, astronomers had never


00:12:01.120 --> 00:12:03.430
found a single case where both stars in


00:12:03.440 --> 00:12:06.470
a binary exploded and both left behind


00:12:06.480 --> 00:12:08.310
remnants we can still see.


00:12:08.320 --> 00:12:10.470
>> Not one out of how many?


00:12:10.480 --> 00:12:13.110
>> We've cataloged around 300 supernova


00:12:13.120 --> 00:12:15.430
remnants in our galaxy. Not one


00:12:15.440 --> 00:12:17.590
confirmed sibling pair. And the reason


00:12:17.600 --> 00:12:19.990
is a bit embarrassing actually. One of


00:12:20.000 --> 00:12:22.230
them was probably sitting in plain sight


00:12:22.240 --> 00:12:23.350
the whole time.


00:12:23.360 --> 00:12:28.150
>> Go on. The Jellyfish Nebula IC 443 in


00:12:28.160 --> 00:12:31.190
the constellation Gemini about 6,000


00:12:31.200 --> 00:12:33.670
lighty years away. It is one of the best


00:12:33.680 --> 00:12:36.150
studied supernova remnants in the sky


00:12:36.160 --> 00:12:38.069
and one of the brightest gamma ray


00:12:38.079 --> 00:12:40.629
sources of its kind. If you could see it


00:12:40.639 --> 00:12:42.790
with your eye, it would look bigger than


00:12:42.800 --> 00:12:44.150
the full moon.


00:12:44.160 --> 00:12:46.710
>> And something was hiding behind it.


00:12:46.720 --> 00:12:49.030
>> Next to it, there's a much fainter


00:12:49.040 --> 00:12:52.069
object called G189.6


00:12:52.079 --> 00:12:55.910
+ 3. It was first picked up in 1994 by


00:12:55.920 --> 00:12:58.870
the German ROSAT satellite as a faint


00:12:58.880 --> 00:13:01.829
X-ray glow and later the Russian German


00:13:01.839 --> 00:13:04.790
Spectrum Ronkin Gamma Observatory saw


00:13:04.800 --> 00:13:06.550
shell-like structures in it which


00:13:06.560 --> 00:13:08.870
suggested it was also a supernova


00:13:08.880 --> 00:13:11.750
remnant but it sits right up against the


00:13:11.760 --> 00:13:14.389
glare of the jellyfish and that glare


00:13:14.399 --> 00:13:15.509
drowns it.


00:13:15.519 --> 00:13:18.310
>> So how did they finally separate them?


00:13:18.320 --> 00:13:21.430
16 years of data from NASA's Fermy Gamma


00:13:21.440 --> 00:13:24.230
Ray Space Telescope. The team led by


00:13:24.240 --> 00:13:27.590
Miltiadis Malites, a post-doal fellow at


00:13:27.600 --> 00:13:30.069
Stanford, essentially subtracted the


00:13:30.079 --> 00:13:32.870
jellyfish out, isolated its gammaray


00:13:32.880 --> 00:13:34.790
emission, and looked at what was left


00:13:34.800 --> 00:13:35.910
underneath.


00:13:35.920 --> 00:13:37.590
>> And there was something left.


00:13:37.600 --> 00:13:40.150
>> There was G189.6


00:13:40.160 --> 00:13:43.430
6 + 3 is independently producing gamma


00:13:43.440 --> 00:13:46.150
rays which matters enormously because


00:13:46.160 --> 00:13:48.790
gamma rays mean particle acceleration


00:13:48.800 --> 00:13:50.949
and particle acceleration is what a


00:13:50.959 --> 00:13:53.509
supernova remnant does. It's the shock


00:13:53.519 --> 00:13:54.870
wave doing work.


00:13:54.880 --> 00:13:57.110
>> Ma's had a nice way of putting that,


00:13:57.120 --> 00:13:57.829
didn't he?


00:13:57.839 --> 00:14:00.069
>> He compared it to a drop of water


00:14:00.079 --> 00:14:02.629
falling on a still lake. The ripples


00:14:02.639 --> 00:14:05.110
spread out from the point of contact. A


00:14:05.120 --> 00:14:07.509
supernova remnant does exactly the same


00:14:07.519 --> 00:14:09.910
thing. And if you can see the ripples,


00:14:09.920 --> 00:14:11.910
you know something dropped.


00:14:11.920 --> 00:14:14.150
>> So, we have two remnants next to each


00:14:14.160 --> 00:14:16.069
other. How do we know they're related


00:14:16.079 --> 00:14:17.990
rather than just an accident of line of


00:14:18.000 --> 00:14:18.629
sight?


00:14:18.639 --> 00:14:20.949
>> This is the elegant part. There's a


00:14:20.959 --> 00:14:23.590
filament of gas arcing between them. And


00:14:23.600 --> 00:14:25.670
that filament is where the shock wave


00:14:25.680 --> 00:14:27.829
from G189.6


00:14:27.839 --> 00:14:30.949
+ 3 has slammed into the same molecular


00:14:30.959 --> 00:14:33.030
cloud that the jellyfish is pushing


00:14:33.040 --> 00:14:33.990
against.


00:14:34.000 --> 00:14:36.550
>> Same cloud. So, same distance.


00:14:36.560 --> 00:14:38.870
>> Same cloud. same distance, same


00:14:38.880 --> 00:14:41.189
neighborhood. They're not one in front


00:14:41.199 --> 00:14:43.509
of the other. They're genuinely next


00:14:43.519 --> 00:14:45.509
door to each other. And that's what


00:14:45.519 --> 00:14:48.069
makes the shared origin story credible.


00:14:48.079 --> 00:14:49.829
>> So, walk me through the story they're


00:14:49.839 --> 00:14:50.550
proposing.


00:14:50.560 --> 00:14:53.509
>> A tale of two massive stars born


00:14:53.519 --> 00:14:55.910
together, gravitationally bound,


00:14:55.920 --> 00:14:59.030
orbiting extremely closely, perhaps only


00:14:59.040 --> 00:15:01.350
a few times the Earth's sun distance


00:15:01.360 --> 00:15:04.069
apart. Close enough that material was


00:15:04.079 --> 00:15:06.550
likely flowing from one to the other.


00:15:06.560 --> 00:15:08.710
And then the bigger one runs out of fuel


00:15:08.720 --> 00:15:10.150
and detonates.


00:15:10.160 --> 00:15:11.990
>> And the explosion breaks the


00:15:12.000 --> 00:15:12.949
partnership.


00:15:12.959 --> 00:15:15.269
>> The explosion breaks the partnership.


00:15:15.279 --> 00:15:17.590
The binary is disrupted and the


00:15:17.600 --> 00:15:19.750
surviving companion is essentially


00:15:19.760 --> 00:15:22.470
kicked, flung off through the galaxy on


00:15:22.480 --> 00:15:25.350
its own. It keeps traveling and tens of


00:15:25.360 --> 00:15:27.750
thousands of years later, it explodes,


00:15:27.760 --> 00:15:28.470
too.


00:15:28.480 --> 00:15:30.550
>> How far apart did they end up? The


00:15:30.560 --> 00:15:33.110
centers of the two explosions are now


00:15:33.120 --> 00:15:35.829
somewhere between 30 and 50 light years


00:15:35.839 --> 00:15:38.389
apart. Two stars that were once close


00:15:38.399 --> 00:15:40.949
enough to be exchanging material now


00:15:40.959 --> 00:15:43.829
separated by that gap and each marked by


00:15:43.839 --> 00:15:45.910
its own expanding shell.


00:15:45.920 --> 00:15:46.949
>> What were they?


00:15:46.959 --> 00:15:49.189
>> The jellyfish's progenitor is thought to


00:15:49.199 --> 00:15:52.310
have been something like 15 to 25 times


00:15:52.320 --> 00:15:55.030
the mass of the sun. Its companion at


00:15:55.040 --> 00:15:58.230
least 20. both were probably tens of


00:15:58.240 --> 00:16:00.389
thousands times more luminous than the


00:16:00.399 --> 00:16:03.749
sun and both may now be neutron stars


00:16:03.759 --> 00:16:05.910
>> and publication status because I know


00:16:05.920 --> 00:16:07.749
this was previewed at a conference.


00:16:07.759 --> 00:16:10.470
>> Good flag. Milti presented the results


00:16:10.480 --> 00:16:12.710
at the American Astronomical Society


00:16:12.720 --> 00:16:15.350
meeting in Pasadena back in June. What's


00:16:15.360 --> 00:16:17.269
happened this week is the peer-reviewed


00:16:17.279 --> 00:16:19.670
paper. It's in Nature Communications


00:16:19.680 --> 00:16:21.749
with the Stanford release and wider


00:16:21.759 --> 00:16:24.069
coverage landing on the 21st.


00:16:24.079 --> 00:16:26.470
>> And one for our listeners. Can we go and


00:16:26.480 --> 00:16:27.749
look at any of this?


00:16:27.759 --> 00:16:30.550
>> Not this month, wherever you are. Gemini


00:16:30.560 --> 00:16:32.870
is close to the sun at the moment, so


00:16:32.880 --> 00:16:35.670
it's lost in the glare globally, but it


00:16:35.680 --> 00:16:37.910
comes back. And this is one where our


00:16:37.920 --> 00:16:39.670
northern hemisphere listeners get the


00:16:39.680 --> 00:16:41.990
better deal. From North America and


00:16:42.000 --> 00:16:44.710
Europe, Gemini rides high overhead


00:16:44.720 --> 00:16:47.590
through winter, December into March, and


00:16:47.600 --> 00:16:49.829
the jellyfish sits beautifully placed


00:16:49.839 --> 00:16:53.030
for a telescope or a long exposure. And


00:16:53.040 --> 00:16:54.230
from down here,


00:16:54.240 --> 00:16:56.550
>> we still get it just lower. From


00:16:56.560 --> 00:16:58.949
Australia and New Zealand, Gemini comes


00:16:58.959 --> 00:17:00.870
up in the northern sky through our


00:17:00.880 --> 00:17:03.590
summer. Visible, worth hunting, but


00:17:03.600 --> 00:17:06.069
closer to the horizon. Either way, put


00:17:06.079 --> 00:17:07.909
it on the list for the end of the year.


00:17:07.919 --> 00:17:09.990
And bear in mind, the jellyfish is


00:17:10.000 --> 00:17:12.069
faint. It would be bigger than the full


00:17:12.079 --> 00:17:14.150
moon if your eye could pick it up, but


00:17:14.160 --> 00:17:16.069
it needs photography or a decent


00:17:16.079 --> 00:17:18.710
aperture to show itself. Anna, here's


00:17:18.720 --> 00:17:20.789
something we know exists, but have never


00:17:20.799 --> 00:17:23.429
actually been able to draw. Galaxy


00:17:23.439 --> 00:17:25.990
clusters. The largest gravitationally


00:17:26.000 --> 00:17:28.150
bound structures in the universe.


00:17:28.160 --> 00:17:30.870
Hundreds or thousands of galaxies plus


00:17:30.880 --> 00:17:33.430
enormous clouds of hot gas plus dark


00:17:33.440 --> 00:17:35.830
matter are threaded through with


00:17:35.840 --> 00:17:37.350
magnetic fields.


00:17:37.360 --> 00:17:39.430
>> We've known that for decades.


00:17:39.440 --> 00:17:41.750
>> What we have never done is map the shape


00:17:41.760 --> 00:17:44.710
of one across an entire cluster from the


00:17:44.720 --> 00:17:47.110
middle right out to the edge. And now


00:17:47.120 --> 00:17:48.230
somebody has


00:17:48.240 --> 00:17:51.190
>> a team led by Andrea Bhuton at INAF,


00:17:51.200 --> 00:17:53.669
Italy's National Astrophysics Institute


00:17:53.679 --> 00:17:55.990
has reconstructed the magnetic field of


00:17:56.000 --> 00:17:59.669
galaxy cluster Abel 2255. And I want to


00:17:59.679 --> 00:18:01.590
be precise about that name because at


00:18:01.600 --> 00:18:03.669
least one outlet has got it wrong this


00:18:03.679 --> 00:18:08.150
week and called it Abel 2142. It is Abel


00:18:08.160 --> 00:18:09.830
2255


00:18:09.840 --> 00:18:11.909
about a billion lighty years away.


00:18:11.919 --> 00:18:13.350
>> Why that cluster?


00:18:13.360 --> 00:18:15.990
>> Because it's famously messy in radio.


00:18:16.000 --> 00:18:19.029
Abel 2255 has long been known for its


00:18:19.039 --> 00:18:21.029
complexity. It's full of strange


00:18:21.039 --> 00:18:23.350
diffused radio structures, halos, and


00:18:23.360 --> 00:18:25.510
filaments, which is exactly what you


00:18:25.520 --> 00:18:27.270
want if you're trying to trace magnetic


00:18:27.280 --> 00:18:29.510
fields because those structures are made


00:18:29.520 --> 00:18:32.150
by energetic electrons spiraling along


00:18:32.160 --> 00:18:33.430
magnetic lines.


00:18:33.440 --> 00:18:35.830
>> So the radio emission is the field


00:18:35.840 --> 00:18:37.590
effectively made visible.


00:18:37.600 --> 00:18:40.390
>> It's the tracer. Electrons corkcrewing


00:18:40.400 --> 00:18:42.710
along magnetic lines give off radio


00:18:42.720 --> 00:18:44.789
waves. So if you can see the emission


00:18:44.799 --> 00:18:47.110
finely enough, you can work backwards to


00:18:47.120 --> 00:18:49.430
the field. The problem has always been


00:18:49.440 --> 00:18:51.669
that these signals are extraordinarily


00:18:51.679 --> 00:18:52.470
faint.


00:18:52.480 --> 00:18:54.150
>> What did they observe with?


00:18:54.160 --> 00:18:56.710
>> Loar, the low frequency array, the


00:18:56.720 --> 00:18:58.950
European radio telescope, spread across


00:18:58.960 --> 00:19:01.430
a continent. And these are the deepest


00:19:01.440 --> 00:19:03.990
radio observations ever made of a galaxy


00:19:04.000 --> 00:19:06.230
cluster. That was combined with a new


00:19:06.240 --> 00:19:08.150
data analysis technique. And between


00:19:08.160 --> 00:19:09.909
them, that's what cracked it.


00:19:09.919 --> 00:19:12.310
>> And what does the map show? This is


00:19:12.320 --> 00:19:14.470
defining. In some regions of the


00:19:14.480 --> 00:19:16.789
cluster, the magnetic field lines are


00:19:16.799 --> 00:19:19.350
strikingly coherent. They follow very


00:19:19.360 --> 00:19:21.750
specific directions, stretching radially


00:19:21.760 --> 00:19:23.669
outward along the extended radial


00:19:23.679 --> 00:19:25.830
structures. They're not random,


00:19:25.840 --> 00:19:27.750
>> which tells you something made them that


00:19:27.760 --> 00:19:28.310
way,


00:19:28.320 --> 00:19:30.390
>> which tells you something is organizing


00:19:30.400 --> 00:19:32.549
them. And Bolton's conclusion is that


00:19:32.559 --> 00:19:34.549
the shape of the field is intimately


00:19:34.559 --> 00:19:36.630
linked to the motion of the gas it sits


00:19:36.640 --> 00:19:39.029
in. The field gets stretched and


00:19:39.039 --> 00:19:41.110
compressed by the movements associated


00:19:41.120 --> 00:19:43.270
with the cluster's own formation.


00:19:43.280 --> 00:19:45.830
>> So the cluster assembling itself is what


00:19:45.840 --> 00:19:47.510
shapes the magnetism.


00:19:47.520 --> 00:19:49.430
>> That's the argument and it's the first


00:19:49.440 --> 00:19:51.750
observational evidence of it. The same


00:19:51.760 --> 00:19:53.909
violent process that builds a galaxy


00:19:53.919 --> 00:19:57.029
cluster. Gas falling in, sloshing,


00:19:57.039 --> 00:19:59.750
colliding, merging is the process that


00:19:59.760 --> 00:20:01.669
combs the magnetic field into the


00:20:01.679 --> 00:20:03.190
pattern we now see.


00:20:03.200 --> 00:20:05.350
>> And that ties into the radio halos


00:20:05.360 --> 00:20:08.230
question. It does. Bolton says they


00:20:08.240 --> 00:20:10.150
believe the mechanism that switches on


00:20:10.160 --> 00:20:12.870
these gigantic radio emissions is linked


00:20:12.880 --> 00:20:14.950
to the formation process of the clusters


00:20:14.960 --> 00:20:17.350
themselves. So, the map isn't just a


00:20:17.360 --> 00:20:19.270
pretty picture. It's the evidence for


00:20:19.280 --> 00:20:20.230
the engine.


00:20:20.240 --> 00:20:22.150
>> It's a lovely example of the thing


00:20:22.160 --> 00:20:24.470
radioastronomy does best.


00:20:24.480 --> 00:20:26.310
>> Showing you a structure that is


00:20:26.320 --> 00:20:28.630
completely invisible, is a billion


00:20:28.640 --> 00:20:30.549
lighty years away, is bigger than


00:20:30.559 --> 00:20:32.470
anything else in the universe, and has


00:20:32.480 --> 00:20:34.950
been sitting there the entire time.


00:20:34.960 --> 00:20:37.669
published in astronomy and astrophysics.


00:20:37.679 --> 00:20:40.070
>> Every if you want to know what has hit


00:20:40.080 --> 00:20:42.470
the earth, don't look at the earth


00:20:42.480 --> 00:20:44.310
>> because the earth keeps erasing it


00:20:44.320 --> 00:20:47.270
>> constantly. Play tectonics, volcanism,


00:20:47.280 --> 00:20:50.230
weather, water, erosion, craters get


00:20:50.240 --> 00:20:53.430
buried, distorted, subducted, destroyed.


00:20:53.440 --> 00:20:55.190
The practical consequence is that


00:20:55.200 --> 00:20:57.510
geological evidence for impacts older


00:20:57.520 --> 00:21:00.630
than about 650 million years is


00:21:00.640 --> 00:21:02.230
extremely scarce here.


00:21:02.240 --> 00:21:04.390
>> And the moon doesn't do any of that. No


00:21:04.400 --> 00:21:07.190
plate tectonics, no flowing water, no


00:21:07.200 --> 00:21:09.430
meaningful atmosphere. The moon just


00:21:09.440 --> 00:21:11.510
keeps the receipts. And when you read


00:21:11.520 --> 00:21:13.270
those receipts carefully, there's a


00:21:13.280 --> 00:21:14.070
spike


00:21:14.080 --> 00:21:14.710
>> when


00:21:14.720 --> 00:21:17.590
>> around 800 million years ago, there's a


00:21:17.600 --> 00:21:19.830
surge in large lunar impacts, and it


00:21:19.840 --> 00:21:22.789
shows up in two independent ways. One is


00:21:22.799 --> 00:21:25.350
the estimated ages of big craters,


00:21:25.360 --> 00:21:28.390
including Capernicus, which is 93 km


00:21:28.400 --> 00:21:31.110
across. The other is impact glass.


00:21:31.120 --> 00:21:33.750
Explain impact glass.


00:21:33.760 --> 00:21:35.669
>> When something hits hard enough, the


00:21:35.679 --> 00:21:38.630
heat melts rock. That melt cools into


00:21:38.640 --> 00:21:41.430
glass and the glass locks in a chemical


00:21:41.440 --> 00:21:43.750
time stamp. The Apollo missions brought


00:21:43.760 --> 00:21:45.830
a lot of it home. And when you look at


00:21:45.840 --> 00:21:48.070
the age distribution of that glass, you


00:21:48.080 --> 00:21:51.590
see the same spike at 800 million years.


00:21:51.600 --> 00:21:53.669
>> So, two different methods agree that


00:21:53.679 --> 00:21:55.590
something happened, but nobody knew


00:21:55.600 --> 00:21:56.149
what.


00:21:56.159 --> 00:21:58.070
>> Nobody knew what. That's the puzzle


00:21:58.080 --> 00:22:00.070
that's been sitting there for decades.


00:22:00.080 --> 00:22:02.870
And a new paper led by Dr. William Bachi


00:22:02.880 --> 00:22:04.870
at the Southwest Research Institute in


00:22:04.880 --> 00:22:07.830
Boulder proposes a specific culprit,


00:22:07.840 --> 00:22:08.710
>> which is


00:22:08.720 --> 00:22:11.669
>> an asteroid called Ulia, or rather the


00:22:11.679 --> 00:22:13.669
parent body of the family of asteroids


00:22:13.679 --> 00:22:16.310
we now call Ulia because the object


00:22:16.320 --> 00:22:18.950
itself no longer exists. It was


00:22:18.960 --> 00:22:21.029
catastrophically broken apart in a


00:22:21.039 --> 00:22:22.710
collision in the main belt.


00:22:22.720 --> 00:22:24.390
>> And the location of that breakup


00:22:24.400 --> 00:22:25.190
matters.


00:22:25.200 --> 00:22:27.750
>> The location is everything. It happened


00:22:27.760 --> 00:22:30.310
right next to what's called the J3:1


00:22:30.320 --> 00:22:32.390
resonance with Jupiter. And a resonance


00:22:32.400 --> 00:22:34.710
like that is essentially a gravitational


00:22:34.720 --> 00:22:37.430
trap door. Material that wanders into it


00:22:37.440 --> 00:22:39.830
gets its orbit pumped up by Jupiter and


00:22:39.840 --> 00:22:42.149
flung into the inner solar system.


00:22:42.159 --> 00:22:44.630
>> So the shrapnel had a delivery mechanism


00:22:44.640 --> 00:22:45.830
waiting right there.


00:22:45.840 --> 00:22:48.149
>> It had an open door right next to it.


00:22:48.159 --> 00:22:50.230
And the simulations show what happened


00:22:50.240 --> 00:22:52.470
in two phases. Half the fragments


00:22:52.480 --> 00:22:53.830
reached the resonance almost


00:22:53.840 --> 00:22:55.590
immediately. That's the prompt


00:22:55.600 --> 00:22:58.070
bombardment. planetary shrapnel sprayed


00:22:58.080 --> 00:22:59.909
across the inner solar system


00:22:59.919 --> 00:23:01.190
>> and the other half


00:23:01.200 --> 00:23:04.310
>> over the following 100 to 150 million


00:23:04.320 --> 00:23:06.630
years another quarter of the fragments


00:23:06.640 --> 00:23:09.029
drifted into the resonance more slowly


00:23:09.039 --> 00:23:11.270
pushed by something called the Yarovsky


00:23:11.280 --> 00:23:11.990
effect


00:23:12.000 --> 00:23:13.909
>> which is what in plain terms


00:23:13.919 --> 00:23:16.470
>> it's sunlight doing work a rotating


00:23:16.480 --> 00:23:19.029
asteroid absorbs sunlight on one side


00:23:19.039 --> 00:23:22.149
and reraiates that heat as it turns that


00:23:22.159 --> 00:23:25.510
riation gives an incredibly gentle push


00:23:25.520 --> 00:23:28.070
on a human scale, it's nothing. Over a


00:23:28.080 --> 00:23:30.310
100 million years, it can move an


00:23:30.320 --> 00:23:32.549
asteroid's orbit enough to drop it into


00:23:32.559 --> 00:23:33.750
a trapoor.


00:23:33.760 --> 00:23:36.070
>> So, this wasn't one bad afternoon. This


00:23:36.080 --> 00:23:37.590
was a long siege.


00:23:37.600 --> 00:23:39.270
>> That's the reframing I think is


00:23:39.280 --> 00:23:41.909
genuinely important here. Not an event,


00:23:41.919 --> 00:23:44.470
an episode, a bombardment that opened


00:23:44.480 --> 00:23:46.630
suddenly and then kept going for well


00:23:46.640 --> 00:23:48.870
over 100 million years.


00:23:48.880 --> 00:23:50.630
>> And what does that mean for Earth?


00:23:50.640 --> 00:23:52.470
>> Here's the number that changes the scale


00:23:52.480 --> 00:23:55.110
of it. For every large impact recorded


00:23:55.120 --> 00:23:57.750
on the moon, roughly 20 similar or


00:23:57.760 --> 00:24:00.070
larger impacts hit the earth where a


00:24:00.080 --> 00:24:02.390
bigger target with stronger gravity.


00:24:02.400 --> 00:24:03.830
>> 20 to one.


00:24:03.840 --> 00:24:07.110
>> 20 to1. So a spike on the moon means a


00:24:07.120 --> 00:24:09.830
barrage down here. And now look at what


00:24:09.840 --> 00:24:12.149
else was happening around 800 million


00:24:12.159 --> 00:24:14.710
years ago. That is the runup to one of


00:24:14.720 --> 00:24:16.870
the most dramatic climate episodes in


00:24:16.880 --> 00:24:19.830
our planet's history. widespread global


00:24:19.840 --> 00:24:21.909
cooling and major shifts in the


00:24:21.919 --> 00:24:23.029
biosphere.


00:24:23.039 --> 00:24:25.510
>> Is he claiming a causal link?


00:24:25.520 --> 00:24:27.750
>> He's careful. And I want to be careful,


00:24:27.760 --> 00:24:30.470
too. Baky's phrasing is that given the


00:24:30.480 --> 00:24:32.870
peak of this barrage coincides with a


00:24:32.880 --> 00:24:35.350
period of widespread cooling and major


00:24:35.360 --> 00:24:37.909
shifts in our biosphere. It is tempting


00:24:37.919 --> 00:24:40.230
to suggest the former produced the


00:24:40.240 --> 00:24:43.269
latter. That is a hypothesis flagged as


00:24:43.279 --> 00:24:46.390
tempting, not a conclusion. Because so


00:24:46.400 --> 00:24:49.190
far only one impact has ever been firmly


00:24:49.200 --> 00:24:51.669
tied to a biological outcome.


00:24:51.679 --> 00:24:54.950
>> Pick shaloo 66 million years ago. The


00:24:54.960 --> 00:24:57.430
end of the dinosaurs. That's the one.


00:24:57.440 --> 00:24:59.590
Everything else is inference.


00:24:59.600 --> 00:25:02.070
>> So how would you ever test this?


00:25:02.080 --> 00:25:04.549
>> This is my favorite part of the paper


00:25:04.559 --> 00:25:06.310
and it's the reason to keep an eye on


00:25:06.320 --> 00:25:09.029
this story. We have asteroid samples on


00:25:09.039 --> 00:25:11.750
Earth right now. Hayabusa 2 brought


00:25:11.760 --> 00:25:14.070
material back from Ryugu in December


00:25:14.080 --> 00:25:17.350
2020. Osiris Rex brought Bennu back in


00:25:17.360 --> 00:25:21.430
September 2023. Both are under analysis.


00:25:21.440 --> 00:25:24.310
>> And if they carry the Ulia fingerprint,


00:25:24.320 --> 00:25:27.029
>> if the minology matches the Ulleia


00:25:27.039 --> 00:25:29.510
family, then we are holding in a


00:25:29.520 --> 00:25:31.830
laboratory physical samples of the


00:25:31.840 --> 00:25:33.990
material that rained on the inner solar


00:25:34.000 --> 00:25:37.590
system 800 million years ago. That would


00:25:37.600 --> 00:25:40.470
turn a dynamical model into a direct


00:25:40.480 --> 00:25:42.149
compositional record.


00:25:42.159 --> 00:25:44.710
>> That's a remarkable thought. Brains in a


00:25:44.720 --> 00:25:47.190
lab in Japan and Texas. That might be


00:25:47.200 --> 00:25:49.510
pieces of the thing that helped freeze


00:25:49.520 --> 00:25:50.630
the Earth.


00:25:50.640 --> 00:25:52.470
>> Published in the Planetary Science


00:25:52.480 --> 00:25:55.430
Journal by Botkkey with Vocritzky, Dyke


00:25:55.440 --> 00:25:56.549
House, and Zelner.


00:25:56.559 --> 00:25:58.470
>> Great. And our next story comes with a


00:25:58.480 --> 00:25:59.990
deadline wherever in the world you're


00:26:00.000 --> 00:26:00.789
listening.


00:26:00.799 --> 00:26:02.149
>> What's the urgency?


00:26:02.159 --> 00:26:04.950
>> The moon. First quarter was yesterday,


00:26:04.960 --> 00:26:08.549
the 21st. Tonight it's a waxing gibbus


00:26:08.559 --> 00:26:10.310
and every night from here it gets


00:26:10.320 --> 00:26:12.870
brighter and stays up longer building to


00:26:12.880 --> 00:26:15.510
the buck moon full at 4:36 in the


00:26:15.520 --> 00:26:18.870
afternoon UTC on Wednesday the 29th.


00:26:18.880 --> 00:26:21.269
That's 10:36 in the morning eastern time


00:26:21.279 --> 00:26:24.149
in the states and 12:36 on Thursday


00:26:24.159 --> 00:26:26.070
morning for us in Australia.


00:26:26.080 --> 00:26:27.909
>> And that matters because of what's


00:26:27.919 --> 00:26:28.870
peaking.


00:26:28.880 --> 00:26:31.909
>> The southern delta Aquarius peak falls


00:26:31.919 --> 00:26:34.310
on the 30th effectively the same night


00:26:34.320 --> 00:26:36.630
as the full moon. So, the peak is going


00:26:36.640 --> 00:26:38.710
to be washed out, which means the


00:26:38.720 --> 00:26:40.230
practical advice is the same for


00:26:40.240 --> 00:26:42.950
everybody. Don't wait for peak night.


00:26:42.960 --> 00:26:44.950
This week is your window in the small


00:26:44.960 --> 00:26:46.950
hours while the moon still sets and


00:26:46.960 --> 00:26:49.430
leaves you real darkness before dawn.


00:26:49.440 --> 00:26:51.909
>> And this is a shower that favors us.


00:26:51.919 --> 00:26:54.549
>> It does. From Australia, New Zealand,


00:26:54.559 --> 00:26:56.870
and southern Africa, the radiant sits


00:26:56.880 --> 00:26:59.430
high close to overhead, which is why the


00:26:59.440 --> 00:27:01.909
shower gets underrated in the north.


00:27:01.919 --> 00:27:04.390
Under genuinely dark skies, you might


00:27:04.400 --> 00:27:07.590
see 15 to 20 an hour. And they're lovely


00:27:07.600 --> 00:27:10.310
meteors, long, graceful streaks rather


00:27:10.320 --> 00:27:12.310
than quick flashes, and known for


00:27:12.320 --> 00:27:14.950
persistent trains, those glowing trails


00:27:14.960 --> 00:27:16.870
that hang in the air for a second or two


00:27:16.880 --> 00:27:17.909
afterwards.


00:27:17.919 --> 00:27:19.830
>> And northern listeners aren't shut out


00:27:19.840 --> 00:27:20.870
of this one.


00:27:20.880 --> 00:27:22.630
>> Not at all. And I want to be clear about


00:27:22.640 --> 00:27:24.549
that because this shower gets written


00:27:24.559 --> 00:27:27.110
off in the north too readily. If you're


00:27:27.120 --> 00:27:29.269
in North America, particularly the


00:27:29.279 --> 00:27:31.669
southern states, Texas, Florida,


00:27:31.679 --> 00:27:34.149
Arizona, the Gulf Coast, the Delta


00:27:34.159 --> 00:27:37.190
Aquar.


00:27:37.200 --> 00:27:39.190
The radiant sits low in your southern


00:27:39.200 --> 00:27:41.750
sky rather than overhead, so you'll see


00:27:41.760 --> 00:27:44.070
fewer of them, but the ones you do catch


00:27:44.080 --> 00:27:46.630
travel long paths across the sky, and


00:27:46.640 --> 00:27:48.870
they can be spectacular. Best time is


00:27:48.880 --> 00:27:51.269
after midnight through to dawn. Southern


00:27:51.279 --> 00:27:53.750
Europe, the Mediterranean, North Africa,


00:27:53.760 --> 00:27:56.549
same deal. And where do people look?


00:27:56.559 --> 00:27:59.029
>> The radiant is in Aquarius near the star


00:27:59.039 --> 00:28:02.149
Delta Aquari. Use fulomalt to find the


00:28:02.159 --> 00:28:04.950
region. But honestly, don't stare at the


00:28:04.960 --> 00:28:07.590
radiant. Lie back, take in as much sky


00:28:07.600 --> 00:28:10.149
as you can, and let them come to you.


00:28:10.159 --> 00:28:13.669
Parent body is suspected to be comet 96P


00:28:13.679 --> 00:28:16.070
Mack Holtz. There are also the Alpha


00:28:16.080 --> 00:28:18.470
Capricornids building to the 30th and


00:28:18.480 --> 00:28:21.990
31st. Far fewer meteors, but famous for


00:28:22.000 --> 00:28:24.470
slow, brilliant fireballs that can punch


00:28:24.480 --> 00:28:26.070
straight through moonlight.


00:28:26.080 --> 00:28:27.909
>> And for the north, there's something


00:28:27.919 --> 00:28:30.070
considerably bigger coming.


00:28:30.080 --> 00:28:32.070
>> There is. And if you're listening in


00:28:32.080 --> 00:28:34.070
North America or Europe, you should be


00:28:34.080 --> 00:28:36.549
planning for this now. Two things land


00:28:36.559 --> 00:28:39.029
together on the 12th of August. First,


00:28:39.039 --> 00:28:41.350
the Perciads peak. And this year, the


00:28:41.360 --> 00:28:43.830
moon is new that same day, which means a


00:28:43.840 --> 00:28:46.470
properly dark sky. That is the best


00:28:46.480 --> 00:28:48.950
perciate year in some time. And the


00:28:48.960 --> 00:28:49.830
second,


00:28:49.840 --> 00:28:53.110
>> a total solar eclipse, the first on


00:28:53.120 --> 00:28:56.389
mainland Europe since 1999 and the first


00:28:56.399 --> 00:29:00.070
in Spain since 1905. Totality sweeps


00:29:00.080 --> 00:29:02.470
across the Arctic, Greenland, Iceland,


00:29:02.480 --> 00:29:04.950
and northern Spain. And in Spain, it


00:29:04.960 --> 00:29:07.110
happens close to sunset with the sun


00:29:07.120 --> 00:29:09.510
only a few degrees above the horizon,


00:29:09.520 --> 00:29:11.830
which could be extraordinary.


00:29:11.840 --> 00:29:14.149
>> North America doesn't get totality this


00:29:14.159 --> 00:29:15.029
time.


00:29:15.039 --> 00:29:17.830
>> No. And I won't oversell it, but there


00:29:17.840 --> 00:29:20.470
is a real partial eclipse across much of


00:29:20.480 --> 00:29:23.110
the continent. Alaska gets the deepest


00:29:23.120 --> 00:29:26.070
view near sunrise. Atlantic Canada gets


00:29:26.080 --> 00:29:28.389
roughly half the sun covered at maximum


00:29:28.399 --> 00:29:30.710
in the afternoon. New England and the


00:29:30.720 --> 00:29:32.950
northeastern states get a smaller bite.


00:29:32.960 --> 00:29:34.789
And there's some coverage visible right


00:29:34.799 --> 00:29:37.350
across every Canadian province and the


00:29:37.360 --> 00:29:39.430
northern contiguous states.


00:29:39.440 --> 00:29:41.669
>> So, dig out the glasses. Dig out the


00:29:41.679 --> 00:29:44.230
Eclipse glasses from 2024 and check


00:29:44.240 --> 00:29:47.750
their ISO12312-2


00:29:47.760 --> 00:29:50.389
certified. It will not get dark. Even


00:29:50.399 --> 00:29:53.269
with 50% coverage, the remaining sun is


00:29:53.279 --> 00:29:55.430
blindingly bright, so there is never a


00:29:55.440 --> 00:29:57.830
safe moment to look without protection.


00:29:57.840 --> 00:29:59.909
And a lovely detail, if you're standing


00:29:59.919 --> 00:30:01.990
in the path of totality in Spain or


00:30:02.000 --> 00:30:04.310
Iceland, there's a genuine chance of a


00:30:04.320 --> 00:30:06.789
percied streaking past during those two


00:30:06.799 --> 00:30:09.750
minutes. And tonight for everyone,


00:30:09.760 --> 00:30:11.909
>> the Milky Way. From the southern


00:30:11.919 --> 00:30:14.310
hemisphere, the galactic core is riding


00:30:14.320 --> 00:30:16.789
high overhead right now. One of the real


00:30:16.799 --> 00:30:19.110
privileges of our winter and it's at its


00:30:19.120 --> 00:30:21.430
best. From the northern hemisphere, it's


00:30:21.440 --> 00:30:24.070
lower in the south towards Sagittarius.


00:30:24.080 --> 00:30:25.750
But on a dark night, it's still


00:30:25.760 --> 00:30:28.630
magnificent. And before dawn, Saturn and


00:30:28.640 --> 00:30:30.710
Mars are in the eastern sky for both


00:30:30.720 --> 00:30:31.909
hemispheres.


00:30:31.919 --> 00:30:33.750
>> One more thing before we go.


00:30:33.760 --> 00:30:36.470
>> The launch watchers. SpaceX is targeting


00:30:36.480 --> 00:30:39.190
Thursday the 23rd for Starship flight


00:30:39.200 --> 00:30:42.470
13. Window opening at 6:45 in the


00:30:42.480 --> 00:30:45.190
evening Eastern time. That's 5:45


00:30:45.200 --> 00:30:48.230
central, 3:45 Pacific and Friday


00:30:48.240 --> 00:30:51.669
morning/4 to 9 for us in Australia. 20


00:30:51.679 --> 00:30:54.389
Starling V3 satellites aboard. Second


00:30:54.399 --> 00:30:56.310
flight of the V3 vehicle.


00:30:56.320 --> 00:30:57.510
>> Dead an alarm.


00:30:57.520 --> 00:30:59.510
>> And as always with Starship, check


00:30:59.520 --> 00:31:01.669
before you commit. The date has already


00:31:01.679 --> 00:31:04.630
moved twice. That's Astronomy Daily for


00:31:04.640 --> 00:31:07.510
Wednesday, the 22nd of July. A mechanic


00:31:07.520 --> 00:31:10.230
on its way to geostationary orbit. A


00:31:10.240 --> 00:31:13.029
rocket stage 2 weeks from making a new


00:31:13.039 --> 00:31:15.990
crater. And 23 astronomers asking the


00:31:16.000 --> 00:31:18.950
world to watch. Two stars that died in


00:31:18.960 --> 00:31:21.110
sequence and left their remnants side by


00:31:21.120 --> 00:31:23.990
side. The first magnetic map of a galaxy


00:31:24.000 --> 00:31:26.310
cluster. And an asteroid breakup that


00:31:26.320 --> 00:31:27.990
may have been raining down on us while


00:31:28.000 --> 00:31:30.870
the Earth froze. Donotes, sources, and


00:31:30.880 --> 00:31:33.669
links are all at astronomyaily.io,


00:31:33.679 --> 00:31:36.230
and you can find us at astrodaily pod


00:31:36.240 --> 00:31:37.669
across the socials.


00:31:37.679 --> 00:31:39.669
>> If you enjoy the show, a rating or


00:31:39.679 --> 00:31:41.669
review genuinely helps other people find


00:31:41.679 --> 00:31:43.750
us. Astronomy Daily is part of the


00:31:43.760 --> 00:31:46.070
byes.com podcast network.


00:31:46.080 --> 00:31:47.110
>> I'm Anna.


00:31:47.120 --> 00:31:49.509
>> And I'm Avery. Get outside this week. It


00:31:49.519 --> 00:31:50.950
won't be dark for long.


00:31:50.960 --> 00:31:55.430
>> Clear skies.


00:31:55.440 --> 00:32:03.269
Stories told


00:32:03.279 --> 00:32:11.190
stories told


00:32:11.200 --> 00:32:13.840
stories